Paper box construction



J. H. LENTINE El' AL Aug. t22, "1939.

PAPER BOX QONSTRUCTION s Sheets-sheet 1 Filed May 14. 1938 /m j, VV

Aug, 22, 1939. J. H. LENTINE r-:T A1. 2,170,759

PAPER BOX CONSTRUCTION Filed May 14, 1938 5 Sheets-Sheet 2 GMM/Man Aug.. 22, 1939. J. H. LENTINE Er A1. 2,170,759

PAPER BOX CONSTRUCTION Filed May 14, 1938 l:s sheets-sheet s FJ; j

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Patented Aug. 22, 1939 UNITED STATES PATENT OFFICE Application May 14, 1938, Serial No. 208,075

17 Claims.

This invention relates to paper box construction.

More specically, the invention relates to a method of and means for corner cutting paper box blanks in combination with they staying thereof.

The method now practiced in the construction of paper or cardboard boxes of the type with which the present invention is concerned, consists in cutting rectangular blanks from sheets `Iof cardboard of a size dependent upon the size `of boxes desired. The blanks are then provided with score lines on which the margins of the blanks are to be bent at right angles to the bodies thereof for forming the si-des and ends of the l-boxes.

'It is, however, necessary to out they corners from the blanks on the score` lines outward of the intersections thereof before bending the margins of the blanks, and this step in the construction of the boxes is at present carried out Eby a separate machine, after which the blanks are stayed (that is, bent and gummed at the corners) by another machine.

The machines now used for corner cutting scored cardboard blanks comprise only one set of cutters, in View of which it is necessary to present the four corners of the blanks to the machine in succession which, of course, requires considerably more time and entails. greater eX- pense than if all four corners were capable of :being out at one time.

While in the interest of economy and time saving, it is the practice to simultaneously cut the corresponding corners from several' of the blanks on such single corner cutting machines, nevertheless ragged edges quite often result and thus impair the quality of the completed boxes.

While machines have been recently proposed for simultaneously cutting all four co-rners from the scored blanks, still they are of complicated construction and prohibitive in price.

After the blanks have been corner-cut as above set forth they are transferred to a staying machine to be completed into box formation by successively bending the margins on the score lines and gumming the corners to maintain such bent margins in position.

It is not only time consuming inthe present method of corner cutting as above set forth but much time is often wasted by the operators of the staying machine in waiting for supplies of corner cut blanks from the corner cutting machines.

Thus, it will be seen that the employment of separate steps and separate machines in the constructionof boxes from scored cardboard blanks is not conducive to maximum economy, which is, of course, the desideratum in the construction of this particular type of boxes, which sell at a relatively low price.

It is a primary object of this invention to provide a method of constructing boxes from scored cardboard blanks wherein the corner cutting and staying are carried out in succession and in a single operation.

It is a further object of the invention to simultaneously cut all four corners from scored cardboard blanks immediately preceding the staying process in a single operation.

It is a still further object of the* invention to provide a quadruple corner cutter in operative association with a staying machine whereby scored cardboard blanks are successively corner cut an-d stayed while the blanks are in a single fixed position.

It is a still further object of the invention to provide a quadruple corner cutter attachment for operative association with existing box staying machines, whereby scored cardboard blanks are capable of being successively corner cut and stayed in single successive operative cycles of the machine. V v

It is a still further object of the invention to provide a method and means whereby the heretofore separate operations of corner cutting and staying scored cardboard blanks are combi-ned, thus resulting in greater economy in pa per box construction. Y

For a more complete understanding of the nature and objects of the invention, reference will now be made to the following detailed description, taken in connection with the accom--V panying drawings, wherein:`

Figure 1 is a perspective view disclosing in dotand-dash lines certain operating parts of an existing and well known paper box staying machine, and disclosing in solid lines the essential elements of the improved corner cutting attachment embodied in the present invention and by which, in cooperation with the machine, the improved method is carried into effect.

Fig. 2 is a similar View particularly disclosing the drive connections between the machine and the attachment.

Fig. 3 is a top plan View of the more essential elements of the corner cutting attachment.

Fig. 4 is a detail perspective view disclosing in particular the relation of the upper and lower knives.

Fig. 5 is an elevational View disclosing a yieldable ejector element.

Fig. 6 is a fragmental perspective view of a corner-cut cardboard blank.

Referring now to the drawings by reference characters, and wherein like characters designate like parts, the letter A designates a paper box staying machine of well known form, and just so much of the machine is shown in dotand-dash lines as to clearly illustrate the application to and operative association of the improved corner cutter attachment therewith.

Such staying machines now in use perform an operation on the scored cardboard blanks subsequent to the corner cutting operation which is known as staying, and which includes the bending of the margins of the blanks and gumming the corners to maintain the bent margins in proper position.

The machine A includes among other essential cooperating elements a crosshead B adjustably supporting a bendng die supporting member C and which is vertically reciprocated by a shaft D.

The present invention is particularly concerned with a corner cutting attachment adapted to simultaneously remove the four corner portions of the scored cardboard blanks in succession immediately preceding the staying operation by the machine A.

The attachment comprises blank guiding and positioning means and is adapted for operative association with the machine whereby the scored cardboard blanks are quadruple corner cut and stayed in one operation and while the blanks are successively in single fixed positions.

v The attachment, in a preferred embodiment thereof, comprises a pair of laterally spaced and vertically disposed posts IIJ which, at their lower ends, are suitably secured to the frame of the machine A.

The posts I at their upper ends support a cross bar II from which are supported the laterally spaced bearings I2. suitably journaled in the posts I0 and bearings I2 is a shaft I3 having secured thereto a bevel gear I4 adjacent each bearing I2. v

Meshing with and driven by each gear I4 is a similar bevel gear I5 which is Xed to one end of a shaft IS. The shafts I6 are parallel and at right angles to shaft I3 and each has its end adjacent gear I5 journaled in a bearing bracket I'I. Each shaft I6 extends through and is suitably journaled in ball bearing assemblies I8 in extensions I9 of castings 20.

o `The castings individually support upper and lower corner cutting knives as well as blank guidmg and positioning means in a manner about to v be described.

The castings are disposed and maintained in rectangular formation and are detachably secured to standard parts of the machine.

Each casting 20 includes an upper U-shaped gib Vand cutter support 2| and a lower foot 22 which is adjustably mounted on the machineadjusting arm E by a bolt 23 whereby provision is made for different thicknesses of cardboard being used.

Adjustably supported in the portion 2l of each oi' the castings 20 is a pair of gibs 24 which provide a vertical guide way for a reciprocable slide 25. The slides 25 are positively reciprocated in unison by cams 26 carried by the shafts I6 and which, in a well known manner, cooperate with blocks laterally movable in'slots 21 in the slides 25.

Each of the slides 25 adjacent the lower end thereof supports a pair of right angularly disposed upper cutting knives 28 for cooperation with a pair of similarly disposed lower cutting knives 29 (Fig. 4) which are secured to the lower portion 30 of the respective castings 20.

The upper knives 28 move within the lower knives 29 in the corner cutting operation and the knives 28 preferably slope downwardly from the juncture thereof to provide for more eicient cutting cooperation with the knives 29. Furthermore, the outer faces of the knives 28 above the cutting edges are preferably inclined, as indicated at 3I in Fig. 5, in order to permit unrestricted movement of the blank margins adjacent the corners in the subsequent bending operation.

The lower portions 39 of the castings 20 each .include an inner downwardly sloping blank corner discharge surface 32 and secured to such portions of each of the castings 29 at the front or feed end of the machine is a blank and guiding plate 33 having its opposite ends curved downwardly, as clearly indicated in Fig. 4, to assure proper movement of the cardboard blanks.

Similarly secured to the casting portions 30 of the rear castings 2B are blank supporting plates 34, each of which is provided at one end with a fixed lug 35 in which is threaded a rod 36 having a swivel connection with a movable gauge lug 3l which is maintained in longitudinal position by a suitable extension thereof riding in a slot 38 in the plate 34. The gauge lugs when properly adjusted are maintained in such adjusted position by thumb screws 39.

At the forward or feed end of the attachment and in guiding alinement with the plates 33 are a pair of adjustable guide bars 49 which are right angular in cross section and which are so disposed relative to the lower knives 29 as to positively avoid jamming of the ends of the blanks with such knives and to assure engagement thereof with the guiding and supporting plates 33.

The bars 4D each has one end of a rod 4I secured to the base thereof, from which point the rod bows upwardly and thence extends laterally for passage through the slot of the respective casting positioning bar, later described, whereby the bars 40 are capable of adjustment both longitudinally and rotatively about rods 4I The bars 40 are maintained in properly adjusted position by means of cooperating nuts 42 and 43.

The blanks are guided from the plates 33 to the plates 34 by longitudinally disposed bars 44 and lateral plates 45 which are suitably secured to the adjustable portions of the frame of the machine A.

The discharge surfaces 32 of the castings 20 of the feed and discharge end of the attachment slope in opposite directions, and operatively associated with such surfaces are discharge chutes 46 at the feed end and 4l at the discharge end.

In order to preclude any possible jamming of the cut out corner portions of the blanks in the castings 20 below the cooperating edges of the cutting knives 28 and 29 each casting 20 preferably has secured thereto, as by a bolt 48, one end of a spring member 49 which, upon downward movement of the respective slide 25, is contacted by a rib 5D thereon, as indicated in Fig. 5, whereby any cut out cornerportions which may be lodged are positively ejected onto the discharge surface 32 of the casting 20.

The shaft i3 is intermittently rotated through drive. QIlneotQnS with the crosshead reciprocating shaft D of the machine A preferably by the following means. y i

Journaled in the post I adjacent one end of shaft I3 is a stub shaft 5I which is operatively connected with the shaft I3 through a yieldable safety clutch device 52 in order to avoid breakage of parts in the event of jamming of the blanks in the corner cutting operation.

Secured to shaft I is a sprocket wheel 52a which is driven by a sprocket chain 53 operatively engaged with a sprocket wheel 54 supported by a shaft 55 journaled in a bracket 56 which is suitably secured to the frame of the machine A.

An idler roller 5l is preferably provided in order to maintain the sprocket chain 53 sufliciently taut for efficient driving engagement with the sprocket wheels. Journaled in the bracket 56 below the shaft 55 is one end of a shaft 58 whose opposite end is journaled at 59 by the opposite post I Il. i

The shaft 58 is continuously driven by means of a sprocket chain 60 operatively engaged with sprocket wheels 6I and B2 fixed to the shafts 58 and D, respectively.

In order to provide intermittent rotation of shaft I3 and retain same against rotation at dwell periods between movement of the slides 25 a combined gear and cam assembly of well known construction is supported by the shafts 55 and 58. This assembly comprises a relatively large disk 63 and cam 64 secured to shaft 58 and a relatively small gear 65 and cam $6 secured to shaft 55.

The disk 33 is provided with teeth of such number as to effect only o-ne rotation of shaft 55 to each rotation of shaft 58. The cam 64 is provided with a well or depression 61 in which the periphery of cam 56 rides when the gear 55 is in mesh with the teeth on disk 63 and the cam 66 `is pro-l vided with a well or depression 68 which is of the same curvature as the concentric portion of cam 64 for engagement therewith to maintain shaft 55 against rotation during rotation of disk 63 Y throughout its toothless peripheral portion.

It will be seen-from the foregoing that the castings 20 which individually support the corner cutting knives and blank supporting and guiding means are secured to the adjustable arms E of the frame of the machine A and, in order to assure and maintain a true rectangular formation of such castings, parallel side bars 'I0 and parallel end bars 'Il are provided. These bars engage the outer plane faces of the castings and are provided with longitudinal slots 'l2 in which are adjustably disposed the anchoring stud bolts 13.l With this arrangement the cutting knives and blank supporting and guiding means are always maintained in accurate position regardless of any adjustment for operation on various sizes of blanks.

From the foregoing disclosure it will be readily seen that we have, in accordance with this invention, provided a corner cutting attachment for scored cardboard blanks which attachment is` quadruple in action in that it cuts all four corners simultaneously, and it will be further seen that the attachment is adapted for ready connection with existing staying machines whereby the sepiarate and distinct operations of corner cutting and staying as at present employed are combined which is illustrated in Fig. 6) are successively fed from a suitable hopper to the guide bars 4I] and thence on to the plates 33, bars 44, and plates 34 until the advancing edges of the blanks contact the gauge lug 3'I.

The blanks are, of course, advanced to this operative position during the dwell periods of the slides 25 and while the bending die is in its upper position. When the blanks are in such position the slides 25 are moved downwardly by the means hereinbefore described and through cooperation of the upper and lower knives the corners are cut from the blank simultaneously, subsequently to which the bending die becomes operative and in cooperation with the vplates 33 and 34 and bars 44 bends the margins of the blanks P on the score lines s with the result that the margins of the blank are brought into right angullarly relation with the body portion of the blank to provide the sides and ends of the box, the corners in accordance with present practice being subsequently secured together by the gumming operation.

Thus it will be seen that the cardboard blanks are successively corner cut and stayed in successive operative cycles of the machine A or, in other Words, upon each revolution of the machine shaft D.

The combination of the corner cutter attachment with the staying machine not only avoids the present experienced delays in operation as above set forth but, due to the fact that the blanks are corner cut individually, the cuts are cleaner than when cut in groups according to present practice whereby a b'etter quality box results.

The corner cutting attachment is relatively simple in construction in that the four castings 20 which are of simple construction individually support the upper and lower cutting knives as well as the blank guiding and positioning plates and, in addition to the corner cutting advantage attained by the attachment, the plates 33 and 34 carried by the castings provide highly efcient means for supporting the blanks and aiding in cooperation with the bending die in bending up the end margins of the blanks. Furthermore, the adjustable lugs 3l readily provide for cutting corners of any desired dimensions, it` being understood that the cutting knives are of a length at least equal to the greatest depth of cut which may be required. l

While we have disclosed `but a single specic embodiment of the improvedmeans for carrying the improved method into effect, nevertheless such is to be considered as illustrative onlyv and `not restrictive, the scope of the invention being defined in the subjoined claims.

What we claim and desire to secure by United` States Letters Patent is: A

l. In combination with a paper box staying machine comprising a reciprocable die for bending the margins of scored cardboard blanks to form the sides and ends of a box; an attachment comprising cooperating cutting knives operatively connected with the machine and disposed adjacent the corner of the die for removing the corner portions of the blanks immediately prior to the bending of the margins thereof by the aforesaid die.

2. A corner cutting attachmentfor operative association with a paper box staying machine which comprises a reciprocable bending die and a shaft for reciprocating same; said attachment 'comprising a plurality of castings for attachment to the machine in rectangular formation,

. in theevent of stationa'ry knives'carried by the castings", `other knives for cooperating with the rst-hand knives movably supported by vthe castings, cardboard blank supporting and positioning means supported by the castings adjacent the fixed knives, and means for yoperative association With the movable `knives and the said shaft for imparting movement to the movable knives for cooperation with the fixed knives in removing .corner portions from the cardboard blanks.

3. The structure defined in claim 2 wherein Said last-named means comprises a pair of parallel shafts each of which is provided with means for imparting movement to the movable knives supported by a pair of said castings and means for imparting intermittent rotation' to said parallel shafts. Y

4. The structure defined in claim 2 together with means for maintaining an accurate rectangular formation of the saidcastings.

5. The structure defined in claim 2 wherein the movable knives come to each ofv said castings are supported by a vertically reciprocable slide and means supported by the casting and operative upon movement of the slide for ejecting previously removed corner blank portions during the successive reciprocation of the slide.

6. In combination with a paper box staying machine comprising a reciprocable cardboard blank bending die and shaft foroperating same, and adjustable arms; an attachment comprising a casting removably secured to each of said arms and with the castings disposed in rectangular formation, bars for maintaining said castings in rectangular formation upon adjustment of said arms, a reciprocableslide supported by each of sai-d castings, fixed corner cutting knives supported by each of said castings, knives supported by each of said slides for cooperation with said fixed knives, cardboard blank guiding and positioning means supported by 'said castings,v and drive connections operatively associated with said slides and said shaft.

7. The structure dei-'ined in claim 6 wherein each of said castings embodies a downwardly inclined discharge surface adjacent the bottom thereof, and discharge chutes for conveying the removed corner portions of the blanks from said discharge surfaces. I

8. The structure dened in claim 6 wherein said drive connections comprise means for imparting intermittent reciprocation toV said slides and means for preventing reciprocation thereof obstruction to the reciprocation thereof. A

9. The structure defined in claim 6 together with guiding and supporting means intermediate the first-named guiding and supporting means and adjustable .guide bars in advance of the guiding and positioning means supported by the castings at the feed end of the machine.

10. A method in the construction of boxes from scored cardboard blanks comprising the following steps; successively advancing scored cardboard blanks to a single operating station, maintainingthe blanks against horizontal displacementV at the single operating station, and

corner cutting and staying the successively advanced blanks in succession at the single operating station.

11. In combination with a paper box staying machine including a reciprocable bending die, a shaft for operating same, and adjustable frame arms; an attachment comprising a casting removably secured to each of said arms with the castings disposed in rectangular formation in surrounding relation to the bending die, a reciprocable slide supported by each of said castings, fixed corner cutting knives supported by each of said castings, knives supported by each of said slides for cooperation with said xed knives, cardboard blank guiding and positioning means supported by said castings, and drive connections between said shaft and said slides.

12. The structure defined in claim 11, wherein said castings are adjustable with respect to said frame arms, and bars adjustably supported by said castings for maintaining same in proper rectangular formation upon adjustment of said arms.

13. The structure defined in claim 11, wherein said drive connections include a pair of parallel and horizontal shafts, each shaft extending through a pair of said castings and having means associated therewith for reciprocating the slides upon rotation of the shaft.

14. In a corner cutting attachment for operative association with a paper box staying machine, a casting for removable and adjustable connection with the machine, said casting comprising an upper U-shaped support, and a lower attaching foot, a pair of gibs adjustably supported in the U-shaped support, providing a vertical guideway, a slide reciprocably mounted in the guideway, a pair of cutting knives supported by said attaching foot, and a pair of cutting knives supported by said slide for cooperation with the first named knives.

15. In combination with a paper box staying machine comprising a reciprocable cardboard bending die, a shaft for operating same, and adjustable frame arms fordeterrnining the sizes of boxes to be stayed; a casting adjustably supported by each of said frame arms, stationary cutters supported by the castings, a slide reciprocably mounted in each of the castings, knives carried by the slides for cooperation with'the rst named knives, and means operatively connected with said shaft for reciprocating said slides.

16. The structure defined in claim 15, wherein said means comprises a pair of shafts, each shaft extending through a pair of said castings, cam engaging means between the shafts and said slides, and drive connections between said pair of shafts and the rst named shaft- 17. In combination with a paper box machine including a staying station, means at said station for quadruple corner cutting scored cardboard blanks immediately preceding the staying operation by said machine at said station.

JOHN HOWARD LENTINE. VICTOR LOIGMAN. 

